The invention relates to a process for the production of a polyolefin-based composite material of high rigidity, said material comprising a polyolefin and a layered clay.
Such a process is known from EP-A-807,659, according to which a modified polyolefin or a polyolefin containing such a modified polyolefin is mixed with a swellable clay in the form of a layered silicate which has been treated (interstratified) with a tetraalkylammonium cation, resulting in a polyolefin-based composite material of high rigidity.
A drawback of said process is that prior to mixing the polyolefin with the silicate, both the silicate and the polyolefin have to be subjected to a pretreatment.